Polymer compound for a conductive polymer and method for producing same

ABSTRACT

The present invention provides a polymer compound for a conductive polymer comprising one or more repeating units “a” shown by the formula (1), and having a weight-average molecular weight in the range of 1,000 to 500,000. There can be provided a polymer compound for a conductive polymer having a specific superacidic sulfo group which is soluble in an organic solvent, and suitably used for a fuel cell or a dopant for a conductive material. 
     
       
         
         
             
             
         
       
     
     wherein R 1  represents a hydrogen atom or a methyl group; R 2  represents any of a single bond, an ester group, and a linear, branched, or cyclic hydrocarbon group having 1 to 12 carbon atoms, the hydrocarbon group optionally containing an ether group, an ester group, or both; “Z” represents any of a single bond, a phenylene group, a naphthylene group, an ether group, and an ester group; and “a” is a number satisfying 0&lt;a≦1.0.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a polymer compound for a conductivepolymer and a method for producing the same.

Description of the Related Art

A polymer containing a sulfo group has been used as a fuel cell or adopant polymer for a conductive polymer. As a material for a fuel cell,vinylperfluoroalkyl ether sulfonic acid represented by Nafion(registered trademark) has been widely used, and as a dopant polymer fora conductive polymer, a polymer of vinylsulfonic acid or styrenesulfonicacid has been widely used (Patent Document 1).

The vinylperfluoroalkyl ether sulfonic acid has chemically highstability and excellent durability, but the glass transition pointthereof is low, so that there is a problem that when a fuel cell usingit is exposed to high temperature, the polymer causes heat flow wherebyion conductivity thereof is lowered. A superacidic polymer having asulfo group an α-position of which has been fluorinated is effective forenhancing the ion conductivity, but a material having high glasstransition point and chemical stability with such a structure has notyet been found out.

Also, a conductive polymer having a conjugated double bond such as apolythiophene, a polyaniline, a polypyrrole, etc., does not exhibitconductivity itself, but conductivity thereof is expressed by dopingtherein a strong acid such as sulfonic acid, etc. As the dopant,polystyrene sulfonic acid (PSS) has been most frequently used. This isbecause conductivity becomes the highest by doping PSS.

PSS is a water-soluble resin, and hardly dissolves in an organicsolvent. Accordingly, a polythiophene using PSS as a dopant is alsowater-soluble.

The polythiophene using PSS as a dopant is highly conductive and highlytransparent, so that it has been expected to be used as a conductivefilm for an organic EL lighting in place of ITO (indium-tin oxide).However, a luminous body of the organic EL chemically changes bymoisture, thereby stopping to emit a light. That is, when a conductivefilm composed of a water-soluble resin is used for an organic EL, thereis a problem that an emission lifetime of the organic EL becomes shortdue to the resin containing water.

PRIOR ART DOCUMENTS Patent Documents

Patent Document 1: Japanese Patent Laid-Open Publication No. 2008-146913

SUMMARY OF THE INVENTION

The present invention has been accomplished in view of theabove-described circumstances, and has an object to provide a polymercompound for a conductive polymer having a specific superacidic sulfogroup which is soluble in an organic solvent, and suitably used for afuel cell or a dopant for a conductive material. In addition, thepresent invention also has an object to provide a method for producingsuch a polymer compound for a conductive polymer.

To solve the above-mentioned problems, the present invention provides apolymer compound for a conductive polymer comprising one or morerepeating units “a” shown by the following general formula (1), andhaving a weight-average molecular weight in the range of 1,000 to500,000,

wherein R¹ represents a hydrogen atom or a methyl group; R² representsany of a single bond, an ester group, and a linear, branched, or cyclichydrocarbon group having 1 to 12 carbon atoms, the hydrocarbon groupoptionally containing either or both of an ether group and an estergroup; “Z” represents any of a single bond, a phenylene group, anaphthylene group, an ether group, and an ester group; and “a” is anumber satisfying 0<a≦1.0.

Such a polymer compound for a conductive polymer can be a polymercompound for a conductive polymer having a specific superacidic sulfogroup which is soluble in an organic solvent, and suitably used for afuel cell or a dopant for a conductive material.

It is preferred that the polymer compound for a conductive polymerfurther comprise a repeating unit “b” shown by the following generalformula (2),

wherein “b” is a number satisfying 0<b<1.0.

When the repeating unit “a” is copolymerized with the repeating unit “b”which is a repeating unit of the polystyrene sulfonic acid, the polymercompound can be used as a dopant polymer with high conductivity.

The repeating unit “a” shown by the general formula (1) preferablyincludes one or more kinds selected from repeating units a1 to a4respectively shown by the following general formulae (3-1) to (3-4),

wherein R¹ has the same meaning as defined above; and a1, a2, a3, and a4are each a number satisfying 0≦a1≦1.0, 0≦a2≦1.0, 0≦a3≦1.0, 0≦a4≦1.0, and0<a1+a2+a3+a4≦1.0.

When such repeating units are included, the polymer compound is moresuitable for a fuel cell or a dopant for a conductive material.

In addition, the present invention provides a method for producing apolymer compound for a conductive polymer containing a repeating unit“a” shown by the following general formula (1), comprising the steps of:

subjecting to polymerization reaction using a monomer having a structureof a salt composed of a sulfonic acid residue and lithium, sodium,potassium, or a nitrogen compound; and after the polymerizationreaction,

converting the structure of the salt composed of a sulfonic acid residueand lithium, sodium, potassium, or a nitrogen compound to a sulfo groupby ion-exchange,

wherein R¹ represents a hydrogen atom or a methyl group; R² representsany of a single bond, an ester group, and a linear, branched, or cyclichydrocarbon group having 1 to 12 carbon atoms, the hydrocarbon groupoptionally containing either or both of an ether group and an estergroup; “Z” represents any of a single bond, a phenylene group, anaphthylene group, an ether group, and an ester group; and “a” is anumber satisfying 0<a1≦1.0.

When such a producing method is employed, the polymer compound for aconductive polymer containing the repeating unit “a” shown by thegeneral formula (1) can be easily produced.

It is preferred that the polymerization reaction using a monomer havinga structure of a salt composed of a sulfonic acid residue and lithium,sodium, potassium, or a nitrogen compound give a polymer which containsa repeating unit shown by the following general formula (4),

wherein R¹, R², “Z”, and “a” have the same meanings as defined above;and “X” represents lithium, sodium, potassium, or a nitrogen compoundshown by the following general formula (5),

wherein R^(101d), R^(101e), R^(101f), R^(101g) each represent a hydrogenatom, or a linear, branched, or cyclic alkyl group, alkenyl group,oxoalkyl group, or oxoalkenyl group each having 1 to 12 carbon atoms, anaryl group having 6 to 20 carbon atoms, or an aralkyl group or anaryloxoalkyl group each having 7 to 12 carbon atoms where a part or allof hydrogen atoms in these groups may be substituted by an alkoxygroup(s); R^(101d) and R^(101e), or R^(101d), R^(101e), and R^(101f) mayform a ring together, and when the ring is formed, R^(101d) andR^(101e), or R^(101d), R^(101e), and R^(101f) represent an alkylenegroup having 3 to 10 carbon atoms or a heteroaromatic ring havingtherein the nitrogen atom in the formula.

Such a repeating unit can be easily converted to the repeating unit “a”shown by the general formula (1) by ion-exchange.

As mentioned above, the polymer compound for a conductive polymer of thepresent invention can be a polymer compound for a conductive polymerhaving a specific superacidic sulfo group which is soluble in an organicsolvent, and suitably used for a fuel cell or a dopant for a conductivematerial.

When this polymer compound for a conductive polymer is used for a fuelcell, a material for a fuel cell having high dielectric constant can beobtained. Also, when this polymer compound is used as a dopant for aconjugated double bond polymer, a conductive film having hightransparency, high conductivity, and high durability can be formed.Since the polymer compound for a conductive polymer of the presentinvention has a superacidic sulfonic-acid structure, the β-position ofwhich has been substituted with trifluoromethyl groups, it exhibits highperformance as a dopant due to the strong ionic bond, and exhibits highstability as an ion. Therefore, when this polymer compound is used as aconductive material, it exhibits high conductivity and high stability.Moreover, it has excellent solubility in an organic solvent, so thatdeterioration of an organic EL device can be prevented by using it for aconductive film for an organic EL lighting.

Further, the producing method of the present invention facilitatesproducing such a polymer compound for a conductive polymer of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As mentioned above, it has been desired to develop a polymer compoundfor a conductive polymer having a specific superacidic sulfa group whichis soluble in an organic solvent, and suitably used for a fuel cell or adopant for a conductive material.

For the purpose of changing a water-soluble conductive polymercontaining water, which causes the deterioration of an organic ELdevice, into an organic solvent-soluble polymer containing an extremelylittle water to prevent the deterioration of the device, the presentinventors have tried to develop a polymer for a dopant having highsolubility in an organic solvent from polystyrene sulfonic acid, whichis a dopant soluble in water but difficultly soluble in an organicsolvent. Since it is effective for increasing solubility in an organicsolvent to introduce a long-chain alkyl group or fluorine, they haveinvestigated to introduce fluorine, and found out that the problems canbe solved particularly by using a polymer compound composed of arepeating unit having a sulfo group, the β-position of which has beensubstituted with trifluoromethyl groups, thereby bringing the inventionto completion.

That is, the present invention is a polymer compound for a conductivepolymer comprising one or more repeating units “a” shown by thefollowing general formula (1), and having a weight-average molecularweight in the range of 1,000 to 500,000,

wherein R¹ represents a hydrogen atom or a methyl group; R² representsany of a single bond, an ester group, and a linear, branched, or cyclichydrocarbon group having 1 to 12 carbon atoms, the hydrocarbon groupoptionally containing either or both of an ether group and an estergroup; “Z” represents any of a single bond, a phenylene group, anaphthylene group, an ether group, and an ester group; and “a” is anumber satisfying 0<a≦1.0.

Hereinafter, the present invention will be described in detail, but thepresent invention is not limited thereto.

Herein, “conductive” means “electrically conductive.”

The inventive polymer compound for a conductive polymer is a polymerwhich contains one or more repeating units “a” shown by the followinggeneral formula (1). The inventive polymer compound for a conductivepolymer can have particularly high transparency by containing therepeating units “a” shown by the following general formula (1),

wherein R¹ represents a hydrogen atom or a methyl group; R² representsany of a single bond, an ester group, and a linear, branched, or cyclichydrocarbon group having 1 to 12 carbon atoms, the hydrocarbon groupoptionally containing either or both of an ether group and an estergroup; “Z” represents any of a single bond, a phenylene group, anaphthylene group, an ether group, and an ester group; and “a” is anumber satisfying 0<a≦1.0.

In the general formula (1), R¹ is a hydrogen atom or a methyl group.

R² is any of a single bond, an ester group, and a linear, branched, orcyclic hydrocarbon group having 1 to 12 carbon atoms, the hydrocarbongroup optionally containing either or both of an ether group and anester group. As the hydrocarbon group, for example, alkylene groups,arylene groups (such as a phenylene group and a naphthylene group),alkenylene groups are mentioned.

“Z” is any of a single bond, a phenylene group, a naphthylene group, anether group, and an ester group.

“a” is a number satisfying 0<a≦1.0.

It is preferred that the repeating unit “a” shown by the general formula(1) include one or more kinds selected from repeating units a1 to a4respectively shown by the following general formulae (3-1) to (3-4),

wherein R¹ has the same meaning as defined above; and a1, a2, a3, and a4are each a number satisfying 0≦a1≦1.0, 0≦a2≦1.0, 0≦a3≦1.0, 0≦a4≦1.0, and0<a1+a2+a3+a4≦1.0.

When such repeating units are included, the polymer compound is moresuitable for a fuel cell or a dopant for a conductive material.

Also, it is preferred that the polymer compound for a conductive polymerof the present invention further contain a repeating unit “b” shown bythe following general formula (2). When the repeating unit “a” iscopolymerized with the repeating unit “b” which is a repeating unit ofthe polystyrene sulfonic acid, the polymer compound can be used as adopant polymer with high conductivity,

wherein “b” is a number satisfying 0<b<1.0.

Also, as explained later, the polymer compound for a conductive polymerof the present invention may further contain a repeating unit “c”besides the repeating unit “a” and the repeating unit “b”.

The polymer compound for a conductive polymer of the present inventionhas a weight-average molecular weight in the range of 1,000 to 500,000,preferably 2,000 to 200,000. If the weight-average molecular weight isless than 1,000, the polymer compound is inferior in heat resistance. Onthe other hand, if the weight-average molecular weight exceeds 500,000,its viscosity is increased, workability is worsened, and solubility inan organic solvent and water is lowered.

The weight-average molecular weight (Mw) is a measured value in terms ofpolystyrene by gel permeation chromatography (GPC) using water,dimethylformamide (DMF), and/or tetrahydrofuran (THF) as a solvent.

The polymer compound for a conductive polymer of the present inventionas mentioned above can be a polymer compound for a conductive polymerhaving a specific superacidic sulfo group which is soluble in an organicsolvent, and suitably used for a fuel cell or a dopant for a conductivematerial.

In addition, the present invention provides a method for producing sucha polymer compound for a conductive polymer of the present invention.

That is, the producing method of the present invention is a method forproducing a polymer compound for a conductive polymer containing arepeating unit “a” shown by the following general formula (1),comprising the steps of:

subjecting to polymerization reaction using a monomer having a structureof a salt composed of a sulfonic acid residue and lithium, sodium,potassium, or a nitrogen compound; and after the polymerizationreaction,

converting the structure of the salt composed of a sulfonic acid residueand lithium, sodium, potassium, or a nitrogen compound to a sulfo groupby ion-exchange,

wherein R¹ represents a hydrogen atom or a methyl group; R² representsany of a single bond, an ester group, and a linear, branched, or cyclichydrocarbon group having 1 to 12 carbon atoms, the hydrocarbon groupoptionally containing either or both of an ether group and an estergroup; “Z” represents any of a single bond, a phenylene group, anaphthylene group, an ether group, and an ester group; and “a” is anumber satisfying 0<a≦1.0.

It is preferred that the polymerization reaction using a monomer havinga structure of a salt composed of a sulfonic acid residue and lithium,sodium, potassium, or a nitrogen compound give a polymer which containsa repeating unit shown by the following general formula (4),

wherein R¹, R², “Z”, and “a” have the same meanings as defined above;and “X” represents lithium, sodium, potassium, or a nitrogen compoundshown by the following general formula (5),

wherein R^(101d), R^(101e), R^(101f), and R^(101g) each represent ahydrogen atom, or a linear, branched, or cyclic alkyl group, alkenylgroup, oxoalkyl group, or oxoalkenyl group each having 1 to 12 carbonatoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group oran aryloxoalkyl group each having 7 to 12 carbon atoms where a part orall of hydrogen atoms in these groups may be substituted by an alkoxygroup(s); R^(101d) and R^(101e), or R^(101d), R^(101e), and R^(101f) mayform a ring together, and when the ring is formed, R^(101d) andR^(101e), or R^(101d), R^(101e), and R^(101f) represent an alkylenegroup having 3 to 10 carbon atoms or a heteroaromatic ring havingtherein the nitrogen atom in the formula.

Such a repeating unit can be easily converted to the repeating unit “a”shown by the general formula (1) by ion-exchange, thereby beingpreferable.

The monomer to be used in the producing method of the present inventionthat has a structure of a salt composed of a sulfonic acid residue andlithium, sodium, potassium, or a nitrogen compound, and can give therepeating unit “a”, may be specifically exemplified by the following.

wherein R¹ has the same meaning as defined above; and “X” representslithium, sodium, potassium, or a nitrogen compound.

Also, as mentioned above, the repeating unit “a” shown by the generalformula (1) preferably includes one or more kinds selected fromrepeating units a1 to a4 respectively shown by the general formulae(3-1) to (3-4). In other words, among the monomers exemplified above,the monomers from which the repeating units a1 to a4 can be obtained areparticularly preferred.

Further, as mentioned above, the polymer compound for a conductivepolymer of the present invention preferably further contains therepeating unit “b” shown by the general formula (2), and a monomer fromwhich the repeating unit “b” can be obtained may be specificallyexemplified by the following,

wherein, X₂ represents a hydrogen atom, lithium, sodium, potassium, anitrogen compound, or a sulfonium compound.

Illustrative examples of X₂ which is a nitrogen compound include acompound shown by the following general formula (5),

wherein R^(101d), R^(101e), R^(101f), and R^(101g) each represent ahydrogen atom, or a linear, branched, or cyclic alkyl group, alkenylgroup, oxoalkyl group, or oxoalkenyl group each having 1 to 12 carbonatoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group oran aryloxoalkyl group each having 7 to 12 carbon atoms where a part orall of hydrogen atoms in these groups may be substituted by an alkoxygroup(s); R^(101d) and R^(101e), or R^(101d), R^(101e), and R^(101f) mayform a ring together, and when the ring is formed, R^(101d) andR^(101e), or R^(101d), R^(101e), and R^(101f) represent an alkylenegroup having 3 to 10 carbon atoms or a heteroaromatic ring havingtherein the nitrogen atom in the formula.

Also, as mentioned above, the polymer compound for a conductive polymerof the present invention may further contain a repeating unit “c”besides the repeating unit “a” and the repeating unit “b”. Examples ofthe repeating unit “c” include styrene types, vinylnaphthalene types,vinylsilane types, acenaphthylene, indene, benzofuran, benzothiophene,(meth)acryl types, vinylcarbazole.

Illustrative examples of a monomer from which the repeating unit “c” canbe obtained may be specifically exemplified by the following.

As a method for synthesizing the polymer compound for a conductivepolymer of the present invention, for example, a method in which desiredmonomers among the above-described monomers are subjected to heatpolymerization in a solvent by adding a radical polymerization initiatorto obtain a polymer compound, which is a copolymer, may be mentioned.

Illustrative examples of the solvent to be used for the polymerizationinclude water, methanol, ethanol, n-propanol, isopropyl alcohol,methoxyethanol, ethoxyethanol, n-butanol, ethylene glycol, propyleneglycol, glycerin, diethylene glycol, dimethylsulfamide,dimethylacetamide, acetone, dimethyl sulfoxide, N-methylpyrrolidone,toluene, benzene, tetrahydrofuran, diethyl ether, dioxane, cyclohexane,cyclopentane, methyl ethyl ketone, and γ-butyrolactone.

Illustrative examples of the radical polymerization initiator includedi-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide,benzoyl peroxide, dilauryl peroxide, cumene hydroperoxide, tert-butylhydroperoxide, tert-butyl peroxyisobutyrate, potassium persulfate,ammonium persulfate, hydrogen peroxide, 2,2′-azobisisobutyronitrile(AIBN), 2,2′-azobis(2,4-dimethylvaleronitrile), dimethyl2,2-azobis(2-methylpropionate), lauroyl peroxide,2,2′-azobis(2-amidinopropane) dihydrochloride, or an alkali metal saltor an ammonium salt of 4,4′-azobis(4-cyanovaleric acid).

The reaction temperature is preferably in the range of 50 to 80° C., andthe reaction time is preferably in the range of 2 to 100 hours, morepreferably 5 to 20 hours.

In the polymer compound for a conductive polymer of the presentinvention, the monomer that gives the repeating unit “a” shown by thegeneral formula (1) may be used alone or in combination with two or morekinds, and it is preferred to combine methacryl type and styrene typemonomers for the sake of enhancing polymerizability.

In addition, two or more kinds of monomers that give the repeating unit“a” may be random-copolymerized, or may be each block-copolymerized.When a block-copolymerized polymer (block copolymer) is used as aconductive film, it can be expected to obtain a merit that theconductivity is improved by aggregating the repeating unit portionscomposed of the two or more kinds of the repeating units “a” with eachother to form a sea-island structure.

Moreover, the monomers that give the repeating units “a” to “c” may berandom-copolymerized, or may be each block-copolymerized. In this case,it can also be expected to obtain a merit that the conductivity isimproved due to the block copolymer as explained for the repeating unit“a” above.

When a random copolymerization is carried out by a radicalpolymerization, the method is generally used in which monomers and aradical polymerization initiator to be used for the copolymerization aremixed and polymerized by heating. In the case that the polymerization isstarted with a first monomer in the presence of a radical polymerizationinitiator, and then adding a second monomer thereto, the resultingpolymer has a structure that the first monomer is polymerized at oneside of the polymer molecule, and the second monomer is polymerized atthe other side. In this case, however, the repeating units of the firstand second monomers are mixedly present at the middle portion, thus ithas a different structure from the block copolymer. For forming theblock copolymer by radical polymerization, living radical polymerizationis preferably used.

In a living radical polymerization method called RAFT polymerization(Reversible Addition Fragmentation chain Transfer polymerization),radicals at the polymer terminal are always living, so that it ispossible to form a block copolymer composed of first and secondrepeating units by starting the polymerization with a first monomer, andthen adding a second monomer at the time when the first monomer has beenconsumed. In addition, it is also possible to form a triblock copolymerby starting the polymerization with a first monomer, then adding asecond monomer at the time when the first monomer has been consumed, andthen adding a third monomer thereto.

When the RAFT polymerization is carried out, there is a characteristicthat a narrowly distributed polymer having a narrow molecular weightdistribution (degree of distribution) is obtained. In particular, whenthe RAFT polymerization is carried out by adding monomers at once, apolymer having a narrower molecular weight distribution can be obtained.

The polymer compound for a conductive polymer of the present inventionpreferably has a narrow distribution, and the molecular weightdistribution (Mw/Mn) thereof is preferably in the range of 1.0 to 2.0,particularly preferably 1.0 to 1.5. The narrow distribution allows toprevent unevenness of the conductivity of the conductive polymersynthesized by using the polymer compound.

To carry out the RAFT polymerization, a chain transfer agent isnecessary, and illustrative examples thereof include2-cyano-2-propylbenzothioate, 4-cyano-4-phenylcarbonothioylthiopentanoicacid, 2-cyano-2-propyldodecyltrithiocarbonate,4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl]pentanoic acid,2-(dodecylthiocarbonothioylthio)-2-methylpropanoic acid,cyanomethyldodecylthiocarbonate,cyanomethylmethyl-(phenyl)carbamothioate, bis(thiobenzoyl)disulfide, andbis(dodecylsulfanylthiocarbonyl)disulfide. Among these,2-cyano-2-propylbenzothioate is particularly preferred.

The proportion of the repeating units “a” to “c” is 0<a≦1.0, 0≦b<1.0,and 0≦c<1.0, preferably 0.1≦a≦0.9, 0.1≦b≦0.9, and 0≦c≦0.8, morepreferably 0.2≦b≦0.8, and 0≦c≦0.5.

Also, it is preferred that a+b+c=1.

Further, when the repeating unit “a” includes one or more kinds selectedfrom repeating units a1 to a4 as mentioned above, it is preferred that0≦a1≦1.0, 0≦a2≦1.0, 0≦a3≦1.0, 0≦a4≦1.0, and 0<a1+a2+a3+a4≦1.0, morepreferably 0≦a1≦0.9, 0≦a2≦0.9, 0≦a3≦0.9, 0≦a4≦0.9, and0.1≦a1+a2+a3+a4≦0.9, much more preferably 0≦a1≦0.8, 0≦a2≦0.8, 0≦a3≦0.8,0≦a4≦0.8, and 0.1≦a1+a2+a3+a4≦0.8.

In the method for producing the polymer compound for a conductivepolymer of the present invention, after polymerizing monomers asmentioned above, the structure of the salt composed of a sulfonic acidresidue and lithium, sodium, potassium, or a nitrogen compound isconverted into a sulfo group by ion-exchange.

At this time, ion-exchange may be carried out by using, for example, anion-exchange resin.

The polymer compound for a conductive polymer containing the repeatingunit “a” shown by the general formula (1) can be easily produced by themethod as mentioned above.

As mentioned above, the polymer compound for a conductive polymer of thepresent invention can be a polymer compound for a conductive polymerhaving a specific superacidic sulfo group which is soluble in an organicsolvent, and suitably used for a fuel cell or a dopant for a conductivematerial.

When this polymer compound for a conductive polymer is used for a fuelcell, a material for a fuel cell having high dielectric constant can beobtained. Also, when this polymer compound is used as a dopant for aconjugated double bond polymer, a conductive film having hightransparency, high conductivity, and high durability can be formed. Theinventive polymer compound for a conductive polymer has a superacidicsulfonic-acid structure, the β-position of which has been substitutedwith trifluoromethyl groups, and accordingly the strong ionic bondbrings a high ability as a dopant and a high stability as an ion.Therefore, this shows high conductivity and stability when used as aconductive material. Moreover, it is excellent in solubility in anorganic solvent, so that deterioration of an organic EL device can beprevented by using it as a conductive film for an organic EL lighting.

Further, the producing method of the present invention facilitatesproducing such a polymer compound for a conductive polymer of thepresent invention.

EXAMPLES

In the following, the present invention is specifically explained byreferring to Examples, but the present invention is not limited thereto.

In the following, monomers used in syntheses of Examples are shown.

Monomer 1: benzyltrimethylammonium3,3,3-trifluoro-2-methacryloyloxy-2-trifluoromethylpropane-1-sulfonateMonomer 2: benzyltrimethylammonium3,3,3-trifluoro-2-(3-methacryloyloxy-1-adamantanecarbonyloxy)-2-trifluoromethylpropane-1-sulfonateMonomer 3: benzyltrimethylammonium3,3,3-trifluoro-2-trifluoromethyl-2-(4-vinylbenzoyloxy)propane-1-sulfonateMonomer 4: tetrabutylammonium3,3,3-trifluoro-2-(4-methacryloyloxy-1-benzoyloxy)-2-trifluoromethylpropane-1-sulfonate

Example 1

Under nitrogen atmosphere, to 37.5 g of methanol stirred at 64° C. wasadded dropwise a solution in which 48.1 g of Monomer 1 and 5.13 g ofdimethyl 2,2′-azobis(isobutyrate) had been dissolved in 112.5 g ofmethanol, over 4 hours. The mixture was further stirred at 64° C. for 4hours. After cooling to room temperature, the mixture was added dropwiseto 1,000 g of ethyl acetate under vigorous stirring. The resulting solidwas collected by filtration, and dried under vacuum at 50° C. for 15hours to obtain 26.2 g of a white polymer.

The obtained white polymer was dissolved in 912 g of pure water, and theammonium salt was converted into a sulfo group by using an ion-exchangeresin. When the obtained polymer was measured by ¹⁹F-NMR, ¹H-NMR, andGPC, the following analytical results were obtained.

Weight-average molecular weight (Mw)=42,000

Molecular weight distribution (Mw/Mn)=1.61

This polymer compound was named Polymer 1.

Example 2

Under nitrogen atmosphere, to 37.5 g of methanol stirred at 64° C. wasadded dropwise a solution in which 24.0 g of Monomer 1, 9.5 g of lithiumstyrenesulfonate, and 5.13 g of dimethyl 2,2′-azobis(isobutyrate) hadbeen dissolved in 112.5 g of methanol, over 4 hours. The mixture wasfurther stirred at 64° C. for 4 hours. After cooling to roomtemperature, the mixture was added dropwise to 1,000 g of ethyl acetateunder vigorous stirring. The resulting solid was collected byfiltration, and dried under vacuum at 50° C. for 15 hours to obtain 41.5g of a white polymer.

The obtained white polymer was dissolved in 912 g of pure water, and theammonium salt and the lithium salt were converted into sulfo groups byusing an ion-exchange resin. When the obtained polymer was measured by¹⁹F-NMR, ¹H-NMR, and GPC, the following analytical results wereobtained.

Copolymer Composition Ratio (Molar Ratio)

-   -   Monomer 1: styrenesulfonic acid=1:1

Weight-average molecular weight (Mw)=46,000

Molecular weight distribution (Mw/Mn)=1.76

This polymer compound was named Polymer 2.

Example 3

Under nitrogen atmosphere, to 37.5 g of methanol stirred at 64° C. wasadded dropwise a solution in which 32.8 g of Monomer 2, 9.5 g of lithiumstyrenesulfonate, and 5.13 g of dimethyl 2,2′-azobis(isobutyrate) hadbeen dissolved in 112.5 g of methanol, over 4 hours. The mixture wasfurther stirred at 64° C. for 4 hours. After cooling to roomtemperature, the mixture was added dropwise to 1,000 g of ethyl acetateunder vigorous stirring. The resulting solid was collected byfiltration, and dried under vacuum at 50° C. for 15 hours to obtain 46.2g of a white polymer.

The obtained white polymer was dissolved in 912 g of pure water, and theammonium salt and the lithium salt were converted into sulfo groups byusing an ion-exchange resin. When the obtained polymer was measured by¹⁹F-NMR, ¹H-NMR, and GPC, the following analytical results wereobtained.

Copolymer Composition Ratio (Molar Ratio)

-   -   Monomer 2: styrenesulfonic acid=1:1

Weight-average molecular weight (Mw)=46,000

Molecular weight distribution (Mw/Mn)=1.52

This polymer compound was named Polymer 3.

Example 4

Under nitrogen atmosphere, to 37.5 g of methanol stirred at 64° C. wasadded dropwise a solution in which 27.0 g of Monomer 3, 9.5 g of lithiumstyrenesulfonate, and 2.82 g of dimethyl 2,2′-azobis(isobutyrate) hadbeen dissolved in 112.5 g of methanol, over 4 hours. The mixture wasfurther stirred at 64° C. for 4 hours. After cooling to roomtemperature, the mixture was added dropwise to 1,000 g of ethyl acetateunder vigorous stirring. The resulting solid was collected byfiltration, and dried under vacuum at 50° C. for 15 hours to obtain 47.3g of a white polymer.

The obtained white polymer was dissolved in 421 g of methanol, and theammonium salt and the lithium salt were converted into sulfo groups byusing an ion-exchange resin. When the obtained polymer was measured by¹⁹F-NMR, ¹H-NMR, and GPC, the following analytical results wereobtained.

Copolymer Composition Ratio (Molar Ratio)

-   -   Monomer 3: styrenesulfonic acid=1:1

Weight-average molecular weight (Mw)=55,000

Molecular weight distribution (Mw/Mn)=1.81

This polymer compound was named Polymer 4.

Example 5

Under nitrogen atmosphere, to 37.5 g of methanol stirred at 64° C. wasadded dropwise a solution in which 34.6 g of Monomer 4, 9.5 g of lithiumstyrenesulfonate, and 2.82 g of dimethyl 2,2′-azobis(isobutyrate) hadbeen dissolved in 112.5 g of methanol, over 4 hours. The mixture wasfurther stirred at 64° C. for 4 hours. After cooling to roomtemperature, the mixture was added dropwise to 1,000 g of ethyl acetateunder vigorous stirring. The resulting solid was collected byfiltration, and dried under vacuum at 50° C. for 15 hours to obtain 50.2g of a white polymer.

The obtained white polymer was dissolved in 421 g of methanol, and theammonium salt and the lithium salt were converted into sulfo groups byusing an ion-exchange resin. When the obtained polymer was measured by¹⁹F-NMR, ¹H-NMR, and GPC, the following analytical results wereobtained.

Copolymer Composition Ratio (Molar Ratio)

-   -   Monomer 4: styrenesulfonic acid=1:1

Weight-average molecular weight (Mw)=56,000

Molecular weight distribution (Mw/Mn)=1.68

This polymer compound was named Polymer 5.

Example 6

Under nitrogen atmosphere, to 37.5 g of methanol stirred at 64° C. wasadded dropwise a solution in which 52.5 g of Monomer 2, 7.0 g of4-(1,1,1,3,3,3-hexafluoro-2-propanol)styrene, and 5.13 g of dimethyl2,2′-azobis(isobutyrate) had been dissolved in 112.5 g of methanol, over4 hours. The mixture was further stirred at 64° C. for 4 hours. Aftercooling to room temperature, the mixture was added dropwise to 1,000 gof ethyl acetate under vigorous stirring. The resulting solid wascollected by filtration, and dried under vacuum at 50° C. for 15 hoursto obtain 43.2 g of a white polymer.

The obtained white polymer was dissolved in 912 g of pure water, and theammonium salt was converted into a sulfo group by using an ion-exchangeresin. When the obtained polymer was measured by ¹⁹F-NMR, ¹H-NMR, andGPC, the following analytical results were obtained.

Copolymer Composition Ratio (Molar Ratio)

-   -   Monomer 2: 4-(1,1,1,3,3,3-hexafluoro-2-propanol)styrene=4:1

Weight-average molecular weight (Mw)=41,000

Molecular weight distribution (Mw/Mn)=1.64

This polymer compound was named Polymer 6.

Example 7

Under nitrogen atmosphere, to 37.5 g of methanol stirred at 64° C. wasadded dropwise a solution in which 52.5 g of Monomer 2, 13.1 g of3,5-bis(2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl)cyclohexylmethacrylate, and 5.13 g of dimethyl 2,2′-azobis(isobutyrate) had beendissolved in 112.5 g of methanol, over 4 hours. The mixture was furtherstirred at 64° C. for 4 hours. After cooling to room temperature, themixture was added dropwise to 1,000 g of ethyl acetate under vigorousstirring. The resulting solid was collected by filtration, and driedunder vacuum at 50° C. for 15 hours to obtain 61.2 g of a white polymer.

The obtained white polymer was dissolved in 912 g of pure water, and theammonium salt was converted into a sulfo group by using an ion-exchangeresin. When the obtained polymer was measured by ¹⁹F-NMR, ¹H-NMR, andGPC, the following analytical results were obtained.

Copolymer Composition Ratio (Molar Ratio)

-   -   Monomer 2:        3,5-bis(2-hydroxy-1,1,1,3,3,3-hexafluoro-2-propyl)cyclohexyl        methacrylate=4:1

Weight-average molecular weight (Mw)=23,000

Molecular weight distribution (Mw/Mn)=1.61

This polymer compound was named Polymer 7.

Polymers 1 to 7 synthesized as mentioned above were each soluble inwater, methanol, ethanol, isopropyl alcohol, propylene glycol monomethylether, tetrahydrofuran, and dimethylformamide.

Thus, the producing method of the present invention facilitatesproducing the polymer compound for a conductive polymer of the presentinvention, which has a specific superacidic sulfonimide group, and issoluble in an organic solvent.

It should be noted that the present invention is not limited to theforegoing embodiment. The embodiment is just an exemplification, and anyexamples that have substantially the same feature and demonstrate thesame functions and effects as those in the technical concept describedin claims of the present invention are included in the technical scopeof the present invention.

What is claimed is:
 1. A polymer compound for a conductive polymercomprising one or more repeating units “a” shown by the followinggeneral formula (1), and having a weight-average molecular weight in therange of 1,000 to 500,000,

wherein R¹ represents a hydrogen atom or a methyl group; R² representsany of a single bond, an ester group, and a linear, branched, or cyclichydrocarbon group having 1 to 12 carbon atoms, the hydrocarbon groupoptionally containing either or both of an ether group and an estergroup; “Z” represents any of a single bond, a phenylene group, anaphthylene group, an ether group, and an ester group; and “a” is anumber satisfying 0<a≦1.0.
 2. The polymer compound for a conductivepolymer according to claim 1, further comprising a repeating unit “b”shown by the following general formula (2),

wherein “b” is a number satisfying 0<b<1.0.
 3. The polymer compound fora conductive polymer according to claim 1, wherein the repeating unit“a” shown by the general formula (1) includes one or more kinds selectedfrom repeating units a1 to a4 respectively shown by the followinggeneral formulae (3-1) to (3-4),

wherein R¹ has the same meaning as defined above; and a1, a2, a3, and a4are each a number satisfying 0≦a1≦1.0, 0≦a2≦1.0, 0≦a3≦1.0, 0≦a4≦1.0, and0<a1+a2+a3+a4≦1.0.
 4. The polymer compound for a conductive polymeraccording to claim 2, wherein the repeating unit “a” shown by thegeneral formula (1) includes one or more kinds selected from repeatingunits a1 to a4 respectively shown by the following general formulae(3-1) to (3-4),

wherein R¹ has the same meaning as defined above; and a1, a2, a3, and a4are each a number satisfying 0≦a1≦1.0, 0≦a2≦1.0, 0≦a3≦1.0, 0≦a4≦1.0, and0<a1+a2+a3+a4≦1.0.
 5. A method for producing a polymer compound for aconductive polymer containing a repeating unit “a” shown by thefollowing general formula (1), comprising the steps of: subjecting topolymerization reaction using a monomer having a structure of a saltcomposed of a sulfonic acid residue and lithium, sodium, potassium, or anitrogen compound; and after the polymerization reaction, converting thestructure of the salt composed of a sulfonic acid residue and lithium,sodium, potassium, or a nitrogen compound to a sulfo group by ionexchange,

wherein R¹ represents a hydrogen atom or a methyl group; R² representsany of a single bond, an ester group, and a linear, branched, or cyclichydrocarbon group having 1 to 12 carbon atoms, the hydrocarbon groupoptionally containing either or both of an ether group and an estergroup; “Z” represents any of a single bond, a phenylene group, anaphthylene group, an ether group, and an ester group; and “a” is anumber satisfying 0<a1≦1.0.
 6. The method for producing a polymercompound for a conductive polymer according to claim 5, wherein thepolymerization reaction using a monomer having a structure of a saltcomposed of a sulfonic acid residue and lithium, sodium, potassium, or anitrogen compound gives a polymer which contains a repeating unit shownby the following general formula (4),

wherein R¹, R², “Z”, and “a” have the same meanings as defined above;and “X” represents lithium, sodium, potassium, or a nitrogen compoundshown by the following general formula (5),

wherein R^(101d), R^(101e), R^(101f), and R^(101g) each represent ahydrogen atom, or a linear, branched, or cyclic alkyl group, alkenylgroup, oxoalkyl group, or oxoalkenyl group each having 1 to 12 carbonatoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group oran aryloxoalkyl group each having 7 to 12 carbon atoms where a part orall of hydrogen atoms in these groups may be substituted by an alkoxygroup(s); R^(101d) and R^(101e), or R^(101d), R^(101e), and R^(101f) mayform a ring together, and when the ring is formed, R^(101d) andR^(101e), or R^(101d), R^(101e), and R^(101f) represent an alkylenegroup having 3 to 10 carbon atoms or a heteroaromatic ring havingtherein the nitrogen atom in the formula.